Glucose, <7 anomer Fischer projection

Comparison of the Fischer (a) and Haworth (b) projections for a- and /3-D-glucose. The Haworth projection is a step closer to reality. Chair configurations for the two anomers of D-glucose are the most accurate depiction (c) but they are not always used because of the difficulty in drawing. Note that the largest substituent, —CH2OH, is in an equatorial location in both structures. The differences between the two anomers are shown in color. 

Q Draw and identify the structures of glucose, its anomers, and its epimers, as Fischer projections and as chair conformations. 

Draw the Fischer projections and the chair conformations of the anomers and epimers of glucose from memory. Identify and name these sugars based on how they differ from the structure of glucose. Problems 23-52 and 53... 

Fischer s open-chain structure for (+)-glucose with its Fischer projection and two (incorrect) cyclic structures for its metiiyl glucosides (top). Haworth s correct assi iment of a six-memhered ring for glucose and Haworth structures for the two anomers of (+)-glucose (bottom)... 

Recognize the structures of other anomers and epimers of glucose, drawn as either Fischer projections orchair structures, by noticing the differences from the glucose structure. 

FIGURE 21.4 Glucose in its cyclic pyranose forms. As explained in t)ie text, two anomers are formed by cyclization of glucose. Tlie molecule wliose newly formed -OH group at Ci is cis to tlie oxygen atom on the lowest chirality center (C5) in a Fischer projection is the a anomer. The molecule whose newly formed -OH group is trans to the oxygen atom on the lowest chirality center in a Fischer projection is the (3 anomer. 

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